File: /usr/src/linux/include/asm-sh/processor.h

1     /*
2      * include/asm-sh/processor.h
3      *
4      * Copyright (C) 1999, 2000  Niibe Yutaka
5      */
6     
7     #ifndef __ASM_SH_PROCESSOR_H
8     #define __ASM_SH_PROCESSOR_H
9     
10     #include <asm/page.h>
11     #include <asm/types.h>
12     #include <linux/threads.h>
13     
14     /*
15      * Default implementation of macro that returns current
16      * instruction pointer ("program counter").
17      */
18     #define current_text_addr() ({ void *pc; __asm__("mova	1f, %0\n1:":"=z" (pc)); pc; })
19     
20     /*
21      *  CPU type and hardware bug flags. Kept separately for each CPU.
22      */
23     enum cpu_type {
24     	CPU_SH7708,		/* Represents 7707, 7708, 7708S, 7708R, 7709 */
25     	CPU_SH7729,		/* Represents 7709A, 7729 */
26     	CPU_SH7750,     /* Represents 7750, 7751 */
27     	CPU_ST40STB1,
28     	CPU_SH_NONE
29     };
30     
31     struct sh_cpuinfo {
32     	enum cpu_type type;
33     	char	hard_math;
34     	unsigned long loops_per_jiffy;
35     
36     	unsigned int cpu_clock, master_clock, bus_clock, module_clock;
37     #ifdef CONFIG_CPU_SUBTYPE_ST40STB1
38     	unsigned int memory_clock;
39     #endif
40     };
41     
42     extern struct sh_cpuinfo boot_cpu_data;
43     
44     #define cpu_data (&boot_cpu_data)
45     #define current_cpu_data boot_cpu_data
46     
47     /*
48      * User space process size: 2GB.
49      *
50      * Since SH7709 and SH7750 have "area 7", we can't use 0x7c000000--0x7fffffff
51      */
52     #define TASK_SIZE	0x7c000000UL
53     
54     /* This decides where the kernel will search for a free chunk of vm
55      * space during mmap's.
56      */
57     #define TASK_UNMAPPED_BASE	(TASK_SIZE / 3)
58     
59     /*
60      * Bit of SR register
61      *
62      * FD-bit:
63      *     When it's set, it means the processor doesn't have right to use FPU,
64      *     and it results exception when the floating operation is executed.
65      *
66      * IMASK-bit:
67      *     Interrupt level mask
68      */
69     #define SR_FD    0x00008000
70     #define SR_IMASK 0x000000f0
71     
72     /*
73      * FPU structure and data
74      */
75     
76     struct sh_fpu_hard_struct {
77     	unsigned long fp_regs[16];
78     	unsigned long xfp_regs[16];
79     	unsigned long fpscr;
80     	unsigned long fpul;
81     
82     	long status; /* software status information */
83     };
84     
85     /* Dummy fpu emulator  */
86     struct sh_fpu_soft_struct {
87     	unsigned long fp_regs[16];
88     	unsigned long xfp_regs[16];
89     	unsigned long fpscr;
90     	unsigned long fpul;
91     
92     	unsigned char lookahead;
93     	unsigned long entry_pc;
94     };
95     
96     union sh_fpu_union {
97     	struct sh_fpu_hard_struct hard;
98     	struct sh_fpu_soft_struct soft;
99     };
100     
101     struct thread_struct {
102     	unsigned long sp;
103     	unsigned long pc;
104     
105     	unsigned long trap_no, error_code;
106     	unsigned long address;
107     	/* Hardware debugging registers may come here */
108     
109     	/* floating point info */
110     	union sh_fpu_union fpu;
111     };
112     
113     #define INIT_THREAD  {						\
114     	sizeof(init_stack) + (long) &init_stack, /* sp */	\
115     	0,					 /* pc */	\
116     	0, 0, 							\
117     	0, 							\
118     	{{{0,}},} 				/* fpu state */	\
119     }
120     
121     /*
122      * Do necessary setup to start up a newly executed thread.
123      */
124     #define start_thread(regs, new_pc, new_sp)	 \
125     	set_fs(USER_DS);			 \
126     	regs->pr = 0;   		 	 \
127     	regs->sr = 0;		/* User mode. */ \
128     	regs->pc = new_pc;			 \
129     	regs->regs[15] = new_sp
130     
131     /* Forward declaration, a strange C thing */
132     struct task_struct;
133     struct mm_struct;
134     
135     /* Free all resources held by a thread. */
136     extern void release_thread(struct task_struct *);
137     /*
138      * create a kernel thread without removing it from tasklists
139      */
140     extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
141     
142     /*
143      * Bus types
144      */
145     #define EISA_bus 0
146     #define EISA_bus__is_a_macro /* for versions in ksyms.c */
147     #define MCA_bus 0
148     #define MCA_bus__is_a_macro /* for versions in ksyms.c */
149     
150     
151     /* Copy and release all segment info associated with a VM */
152     #define copy_segments(p, mm)	do { } while(0)
153     #define release_segments(mm)	do { } while(0)
154     
155     /*
156      * FPU lazy state save handling.
157      */
158     
159     static __inline__ void release_fpu(void)
160     {
161     	unsigned long __dummy;
162     
163     	/* Set FD flag in SR */
164     	__asm__ __volatile__("stc	sr, %0\n\t"
165     			     "or	%1, %0\n\t"
166     			     "ldc	%0, sr"
167     			     : "=&r" (__dummy)
168     			     : "r" (SR_FD));
169     }
170     
171     static __inline__ void grab_fpu(void)
172     {
173     	unsigned long __dummy;
174     
175     	/* Clear out FD flag in SR */
176     	__asm__ __volatile__("stc	sr, %0\n\t"
177     			     "and	%1, %0\n\t"
178     			     "ldc	%0, sr"
179     			     : "=&r" (__dummy)
180     			     : "r" (~SR_FD));
181     }
182     
183     extern void save_fpu(struct task_struct *__tsk);
184     
185     #define unlazy_fpu(tsk) do { 			\
186     	if ((tsk)->flags & PF_USEDFPU) {	\
187     		grab_fpu();			\
188     		save_fpu(tsk); 			\
189     	}					\
190     } while (0)
191     
192     #define clear_fpu(tsk) do { 			\
193     	if ((tsk)->flags & PF_USEDFPU)	 	\
194     		(tsk)->flags &= ~PF_USEDFPU; 	\
195     } while (0)
196     
197     /* Double presision, NANS as NANS, rounding to nearest, no exceptions */
198     #define FPSCR_INIT  0x00080000
199     
200     /*
201      * Return saved PC of a blocked thread.
202      */
203     static __inline__ unsigned long thread_saved_pc(struct thread_struct *t)
204     {
205     	return t->pc;
206     }
207     
208     extern unsigned long get_wchan(struct task_struct *p);
209     
210     #define KSTK_EIP(tsk)  ((tsk)->thread.pc)
211     #define KSTK_ESP(tsk)  ((tsk)->thread.sp)
212     
213     #define THREAD_SIZE (2*PAGE_SIZE)
214     extern struct task_struct * alloc_task_struct(void);
215     extern void free_task_struct(struct task_struct *);
216     #define get_task_struct(tsk)      atomic_inc(&virt_to_page(tsk)->count)
217     
218     #define init_task	(init_task_union.task)
219     #define init_stack	(init_task_union.stack)
220     
221     #endif /* __ASM_SH_PROCESSOR_H */
222